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Cocoa Core Data efficient way to count entities
I read much about Core Data.. but what is an efficient way to make a count over an Entity-Type (like SQL can do with SELECT count(1) ...). Now I just solved this task with selecting all with NSFetchedResultsController and getting the count of the NSArray ! I am sure this is not the best way...
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In Java, what does NaN mean?
...wered Apr 11 '10 at 17:59
Mike DanielsMike Daniels
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Separators for Navigation
I need to add separators between elements of navigation. Separators are images.
9 Answers
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Passing a dictionary to a function as keyword parameters
...s for the detailed response. Do you know any ways to work around case 3? Meaning pythonically map the items of the dictionary to the function parameters, when there are more items in the dictionary than there are parameters?
– spencer
Apr 25 '19 at 14:22
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Insert all values of a table into another table in SQL
... I believe it'll throw an error and roll back the transaction, meaning nothing gets copied. Worth testing though.
– Matt Hamilton
Jun 17 '09 at 21:01
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mysql Foreign key constraint is incorrectly formed error
I have two tables, table1 is the parent table with a column ID and table2 with a column IDFromTable1 (not the actual name) when I put a FK on IDFromTable1 to ID in table1 I get the error Foreign key constraint is incorrectly formed error . I would like to delete table 2 record if tab...
What's the difference between text/xml vs application/xml for webservice response
...e with a text/xml header" also is this verified?
– Shanimal
Apr 26 '12 at 14:47
I agree with @Shanimal, the answer sho...
How to find out if a Python object is a string?
How can I check if a Python object is a string (either regular or Unicode)?
15 Answers
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What are the best practices for using a GUID as a primary key, specifically regarding performance?
I have an application that uses GUID as the Primary Key in almost all tables and I have read that there are issues about performance when using GUID as Primary Key. Honestly, I haven't seen any problem, but I'm about to start a new application and I still want to use the GUIDs as the Primary Keys, b...
Remove items from one list in another
I'm trying to figure out how to traverse a generic list of items that I want to remove from another list of items.
9 Answer...